<template>
  <div>
    <!-- 面包屑导航区 -->
    <el-breadcrumb separator-class="el-icon-arrow-right">
      <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
      <el-breadcrumb-item>商品管理</el-breadcrumb-item>
      <el-breadcrumb-item>参数列表</el-breadcrumb-item>
    </el-breadcrumb>

    <!-- 卡片视图区域 -->
    <el-card>
      <!-- 警告区 -->
      <!-- show-icon  显示前面的叹号提示图标
      :closable="false"   去掉叉号，一直显示的提示框 -->
      <el-alert show-icon title="注意：只允许为第三级分类设置相关参数！" type="warning" :closable="false">
      </el-alert>

      <!-- 选择商品分类区域 -->
      <el-row class="cat_opt">
        <el-col>
          <span>选择商品分类：</span>
          <!-- 选择商品分类的级联选择框 -->
          <el-cascader expand-trigger="hover" :options="catelist" :props="cateProps" v-model="selectedCateKeys"
            @change="handleChange">
          </el-cascader>
        </el-col>
      </el-row>

      <!-- tab 页签区域 -->
      <el-tabs v-model="activeName" @tab-click="handleTabClick">
        <!-- 添加动态参数的面板 -->
        <el-tab-pane label="动态参数" name="many">
          <!-- 添加参数的按钮 -->
          <el-button type="primary" size="mini" :disabled="isBtnDisabled" @click="addDialogVisible=true">添加参数
          </el-button>
          <!-- 动态参数表格 -->
          <el-table :data="manyTableData" border stripe>
            <!-- 展开行 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环渲染Tag标签 -->
                <el-tag v-for="(item,i) in scope.row.attr_vals" :key="i" closable @close="handleClose(i,scope.row)">
                  {{item}}</el-tag>
                <!-- 输入的文本框 -->
                <el-input class="input-new-tag" v-if="scope.row.inputVisible" v-model="scope.row.inputValue"
                  ref="saveTagInput" size="small" @keyup.enter.native="handleInputConfirm(scope.row)"
                  @blur="handleInputConfirm(scope.row)">
                </el-input>
                <!-- 添加按钮 -->
                <el-button v-else class="button-new-tag" size="small" @click="showInput(scope.row)">+ New Tag
                </el-button>
              </template>
            </el-table-column>
            <!-- 索引列 -->
            <el-table-column type="index"></el-table-column>
            <el-table-column label="参数名称" prop="attr_name"></el-table-column>
            <el-table-column label="操作">
              <template slot-scope="scope">
                <el-button size="mini" type="primary" icon="el-icon-edit" @click="showEditDialog(scope.row.attr_id)">编辑
                </el-button>
                <el-button size="mini" type="danger" icon="el-icon-delete" @click="removeParams(scope.row.attr_id)">删除
                </el-button>
              </template>
            </el-table-column>
          </el-table>
        </el-tab-pane>
        <!-- 添加静态属性的面板 -->
        <el-tab-pane label="静态属性" name="only">
          <!-- 添加属性的按钮 -->
          <el-button type="primary" size="mini" :disabled="isBtnDisabled" @click="addDialogVisible=true">添加属性
          </el-button>
          <!-- 静态属性表格 -->
          <el-table :data="onlyTableData" border stripe>
            <!-- 展开行 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环渲染Tag标签 -->
                <el-tag v-for="(item,i) in scope.row.attr_vals" :key="i" closable @close="handleClose(i,scope.row)">
                  {{item}}</el-tag>
                <!-- 输入的文本框 -->
                <el-input class="input-new-tag" v-if="scope.row.inputVisible" v-model="scope.row.inputValue"
                  ref="saveTagInput" size="small" @keyup.enter.native="handleInputConfirm(scope.row)"
                  @blur="handleInputConfirm(scope.row)">
                </el-input>
                <!-- 添加按钮 -->
                <el-button v-else class="button-new-tag" size="small" @click="showInput(scope.row)">+ New Tag
                </el-button>
              </template>
            </el-table-column>
            <!-- 索引列 -->
            <el-table-column type="index"></el-table-column>
            <el-table-column label="属性名称" prop="attr_name"></el-table-column>
            <el-table-column label="操作">
              <template slot-scope="scope">
                <el-button size="mini" type="primary" icon="el-icon-edit" @click="showEditDialog(scope.row.attr_id)">编辑
                </el-button>
                <el-button size="mini" type="danger" icon="el-icon-delete" @click="removeParams(scope.row.attr_id)">删除
                </el-button>
              </template>
            </el-table-column>
          </el-table>
        </el-tab-pane>
      </el-tabs>
    </el-card>

    <!-- 添加参数的对话框 -->
    <el-dialog :title="'添加'+titleText" :visible.sync="addDialogVisible" width="50%" @close="addDialogClosed">
      <!-- 添加参数的表单 -->
      <el-form :model="addForm" :rules="addFormRules" ref="addFormRef" label-width="100px">
        <el-form-item :label="titleText" prop="attr_name">
          <el-input v-model="addForm.attr_name"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="addDialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="addParams">确 定</el-button>
      </span>
    </el-dialog>

    <!-- 修改参数的对话框 -->
    <el-dialog :title="'修改'+titleText" :visible.sync="editDialogVisible" width="50%" @close="editDialogClosed">
      <!-- 添加参数的表单 -->
      <el-form :model="editForm" :rules="editFormRules" ref="editFormRef" label-width="100px">
        <el-form-item :label="titleText" prop="attr_name">
          <el-input v-model="editForm.attr_name"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="editDialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="editParams">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
  export default {
    data() {
      return {
        // 商品分类列表
        catelist: [],
        // 级联选择框的配置对象
        cateProps: {
          value: 'cat_id',
          label: 'cat_name',
          children: 'children'
        },
        // 级联选择框双向绑定到的数组
        selectedCateKeys: [],
        // 被激活的页签的名称
        activeName: 'many',
        // 动态参数的数据
        manyTableData: [],
        // 静态属性的数据
        onlyTableData: [],
        // 控制添加参数对话框的显示与隐藏
        addDialogVisible: false,
        // 添加参数的表单数据对象
        addForm: {
          attr_name: ''
        },
        // 添加表单的验证规则对象
        addFormRules: {
          attr_name: [{
            required: true,
            message: '请输入参数名称',
            trigger: 'blur'
          }]
        },
        // 控制编辑修改对话框的显示与隐藏
        editDialogVisible: false,
        // 修改的表单数据对象
        editForm: {},
        // 修改表单的验证规则对象
        editFormRules: {
          attr_name: [{
            required: true,
            message: '请输入参数名称',
            trigger: 'blur'
          }]
        },


      }
    },
    created() {
      this.getCateList()
    },
    methods: {
      // 获取所有商品分类列表
      async getCateList() {
        const {
          data: res
        } = await this.$http.get('categories')
        if (res.meta.status !== 200) {
          return this.$message.erroe('获取商品分类失败！')
        }

        this.catelist = res.data
      },
      // 级联选择框选中项变化时，触发该函数
      handleChange() {
        this.getParamsData()
      },
      // tab 页签点击事件的处理函数
      handleTabClick() {
        this.getParamsData()
      },
      // 获取参数的列表数据
      async getParamsData() {
        // 如果已选的对象数组长度没有3，证明选中的不是三级分类，清空已选对象数组，并返回
        if (this.selectedCateKeys.length !== 3) {
          this.selectedCateKeys = []
          this.manyTableData = []
          this.onlyTableData = []
          return
        }

        // 根据所选分类的id，和当前所处的面板,获取对应的参数
        const {
          data: res
        } = await this.$http.get(`categories/${this.cateId}/attributes`, {
          params: {
            sel: this.activeName
          }
        })

        if (res.meta.status !== 200) {
          return this.$message.error('获取参数列表失败！')
        }

        // 将原本以空格为间隔的attr_vals字符串转化为一个 attr_vals数组
        res.data.forEach(item => {
          item.attr_vals = item.attr_vals ? item.attr_vals.split(' ') : []
          // 控制文本框的显示与隐藏
          item.inputVisible = false
          // 文本框中输入的值
          item.inputValue = ''
        })

        // 判断获得的数据是 动态参数面板的 还是 静态属性面板的
        if (this.activeName === 'many') {
          this.manyTableData = res.data
        } else {
          this.onlyTableData = res.data
        }
      },
      // 监听添加对话框的关闭事件
      addDialogClosed() {
        this.$refs.addFormRef.resetFields()
      },
      // 点击确定按钮,添加参数
      addParams() {
        // 预验证
        this.$refs.addFormRef.validate(async valid => {
          if (!valid) return
          const {
            data: res
          } = await this.$http.post(`categories/${this.cateId}/attributes`, {
            attr_name: this.addForm.attr_name,
            attr_sel: this.activeName
          })

          if (res.meta.status !== 201) {
            return this.$message.error('添加参数失败!')
          }

          this.$message.success('添加参数成功!')
          this.addDialogVisible = false
          this.getParamsData()
        })
      },
      // 点击编辑按钮,显示修改参数的对话框
      async showEditDialog(attr_id) {
        // 获取当前参数的信息,将已选的这行参数名显示到文本框中
        const {
          data: res
        } = await this.$http.get(`categories/${this.cateId}/attributes/${attr_id}`, {
          params: {
            attr_sel: this.activeName
          }
        })

        if (res.meta.status !== 200) {
          return this.$message.error('获取参数信息失败!')
        }

        this.editForm = res.data
        this.editDialogVisible = true
      },
      // 重置修改的表单
      editDialogClosed() {
        this.$refs.editFormRef.resetFields()
      },
      // 点击确定按钮,修改参数信息
      editParams() {
        this.$refs.editFormRef.validate(async valid => {
          if (!valid) return
          const {
            data: res
          } = await this.$http.put(`categories/${this.cateId}/attributes/${this.editForm.attr_id}`, {
            attr_name: this.editForm.attr_name,
            attr_sel: this.activeName
          })

          if (res.meta.status !== 200) {
            return this.$message.erroe('修改参数失败!')
          }

          this.$message.success('修改参数成功!')
          this.getParamsData()
          this.editDialogVisible = false
        })
      },
      // 根据参数id 删除对应的参数项
      async removeParams(attr_id) {
        // 删除操作要弹出确认提示框
        // $confirm会返回一个promise; 不需要解构,因为返回的是一个文本
        const confirmResult = await this.$confirm('此操作将永久删除该参数, 是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).catch(err => err)

        if (confirmResult !== 'confirm') {
          return this.$message.info('已取消删除!')
        }

        // 确定删除,删除操作:
        const {
          data: res
        } = await this.$http.delete(`categories/${this.cateId}/attributes/${attr_id}`)

        if (res.meta.status !== 200) {
          return this.$message.error('删除参数失败!')
        }

        this.$message.success('删除参数成功!')
        this.getParamsData()
      },
      // 文本框失去焦点 或按下回车键 都会触发文本提交
      async handleInputConfirm(row) {
        if (row.inputValue.trim().length === 0) {
          row.inputValue = ''
          row.inputVisible = false
          return
        }
        // 如果没有return, 则证明输入了内容, 就将新输入的内容push到attr_vals数组中
        row.attr_vals.push(row.inputValue.trim())
        row.inputValue = ''
        row.inputVisible = false

        // 发起请求,持久化保存此次操作
        this.savaAttrVals(row)
      },
      // 将对 attr_vals 的操作,保存到数据库
      async savaAttrVals(row) {
        // 发起请求,持久化保存此次操作
        // row.attr_vals.join(' ')通过空格将他们拼接成后台字符串的形式
        const {
          data: res
        } = await this.$http.put(`categories/${this.cateId}/attributes/${row.attr_id}`, {
          attr_name: row.attr_name,
          attr_sel: row.attr_sel,
          attr_vals: row.attr_vals.join(' ')
        })

        if (res.meta.status !== 200) {
          return this.$message.error('修改参数项失败!')
        }

        this.$message.success('修改参数项成功!')
      },
      // 点击按钮,显示文本输入框
      showInput(row) {
        row.inputVisible = true
        // 让文本框自动获得焦点
        // $nextTick方法的作用:当页面上元素被重新渲染后,才会指定回调函数中的代码(当row.inputVisible = true执行后页面被渲染后才执行)
        // this.$refs.saveTagInput.$refs.input 获取了input的DOM元素
        this.$nextTick(_ => {
          this.$refs.saveTagInput.$refs.input.focus();
        });
      },
      // 删除小按钮 删除对应的参数可选项
      handleClose(i, row) {
        row.attr_vals.splice(i, 1)
        this.savaAttrVals(row)
      }
    },
    computed: {
      // 如果按钮需要被禁用，则返回true，否则返回false
      isBtnDisabled() {
        if (this.selectedCateKeys.length !== 3) {
          return true
        }
        return false
      },
      // 当前选中的三级分类id
      cateId() {
        if (this.selectedCateKeys.length === 3) {
          return this.selectedCateKeys[2]
        }
        return null
      },
      // 动态计算标题的文本
      titleText() {
        if (this.activeName === 'many') {
          return '动态参数'
        }
        return '静态属性'
      },

    }
  }
</script>

<style lang="less" scoped>
  .cat_opt {
    margin: 15px 0;
  }

  .el-tag {
    margin: 10px;
  }

  .input-new-tag {
    width: 120px;
  }
</style>